Abstract: An arrangement for the control of an operating installation of a building automation system is disclosed. The arrangement comprises a control module serving as a master transmitter-receiver and at least one function module serving as a slave transmitter receiver. A bus connection including a bus rail connects the control module and the at least one function module for the transmission of addresses and data and for the transmission of operating voltages. The bus rail is installed electrically at the periphery of the installation so that the at least one function module is connected to a plurality of conductors forming the bus rail and directly to the installation so that the function module serves as an input/output terminal of said installation for the transmission of process parameters.

Abstract: An article of manufacture contains a substrate which supports a diffraction element divided into surface portions having optically-active microscopic relief structures. At least one pair of surface portions is mirror-symmetric with respect to the orientation of the corresponding relief structures. Each surface portion of the pair has an optically-active, microscopic, asymmetric relief structure defined by an orientation azimuth angle. The azimuth angles are 180.degree. apart. The mirror symmetric pairs constitute optical markings which are machine-readable. The readout device generates an incident light beam and contains photosensors and electronics to output the intensity difference between pairs of diffracted light beams. Alternatively, each surface portion of the diffraction element has a volume hologram rather than a microscopic relief structure for diffracting incident light.

Abstract: An article of manufacture contains a substrate which contains a bar code field containing bar elements and background elements. The bar code elements have embossed, optically-reactive, microscopic periodic, relief structures which are suitable for optical-machine readout. A readout device generates an incident light beam and contains photosensors to detect the diffracted light beams.

Abstract: A Hall element has a polygonal plane cross-section. In the cross-sectional plane, on the sides of the cross-section, are cross-sections of electrodes, the number of which is a multiple of four. The locations and cross-sections of the electrodes are mathematically conformal mappings into the polygonal plane cross-section of a fictitious group of non-overlapping cross-sections of electrodes in equal number transformed from a fictitious plane in which they are arranged radially symmetric on the circumference of a circle. The radius of the circle is equal to one. The fictitious group is sub-divided into groups of four within which the cross-sections of the corresponding fictitious electrodes are always at the same distances to each other on the circumference of the circle.

Abstract: A blower burner capable of operating in two burner steps comprises a drive for an air throttle capable of running in a first direction from closed to open and in a second direction from open to closed, an auxiliary switch connected to the drive of the air throttle, a latch-free no-voltage relay, and a single-wire relay. The auxiliary switch is activated by the drive when the drive is running towards open position before the air throttle reaches the set position for the first burner step. The no-voltage relay is excited upon activation by the auxiliary switch. The single-wire relay operates under the control of the latch-free, no-voltage relay to cause the drive to switch over to drive towards the closed position after a built-in delay when the no-voltage relay has been excited.

Abstract: A device for measuring a weak magnetic field is disclosed. The device includes a substrate, a magnetic core having a high magnetic permeability and in the form of a surface film on a substrate, and at least two coils magnetically coupled to the magnetic core. A pulse generator is connected to one of the coils and is used to drive the magnetic core into intermittent saturation. The other coil is used to generate an output signal. The device can be used for measuring the weak magnetic fields associated with bank notes for identifying the values of the bank notes.

Abstract: In an integrable Hall element, which includes a semiconductor layer of a single conductive type, a plurality of current electrodes adapted for being connected to an energy source, and wherein at least one current electrode and two sensor electrodes are located on a surface of the Hall element, and the one current electrode has a first connecting contact forming a first energy source pole, the improvement consists in the one current electrode being approximately located in the center of a line connecting the sensor electrodes.

Abstract: A document with an embossed macroscopic structure and acting through optical diffraction is disclosed. The structure, which serves as a security element comprises a plurality of surface portions with predetermined relief structures having spatial frequencies of over 10 lines/mm. Each surface portion is different from directly adjoining surface portions and at least some of the surface portions have a maximum dimension of less than 0.3 mm. To the naked eye, the pattern of surface portions on the document appears as a mesh of dots and lines. However, to an examiner with a magnifying device, the dots and lines appear as numbers, characters or other graphic features.

Abstract: A memory device for digital electronic signals includes at least one micro-mechanical memory element. The memory element includes a support having recess defined therein and a curved mechanical component bridging the recess and fixed to the support. The mechanical component has two stable positions, each of which being maintained by mechanical forces, one concave down towards the support and the other convex up away from the support. The mechanical component is adapted to be selectively changed from one stable position to the other stable position during a writing cycle and to have its stable position determined during a reading cycle so that the memory element can be used for storing binary logic information.

Abstract: An arrangement which eliminates or reduces the negative influence of small variations in the charge-carrier concentration of a semiconductor material upon the longterm stability of a magnetic field sensor such as a Hall element is disclosed. In an illustrative embodiment, the arrangement comprises a magnetic field sensor, a voltage/current converter which provides a supply current to the magnetic field sensor, an amplifier connected sequentially downstream of the voltage/frequency converter, and an analog/digital or voltage/frequency converter connected sequentially downstream of the amplifier. The amplifier provides a transmission ratio which is proportional to (1+.delta.n/n) or (1-.delta.n/n) where n is the carge-carrier concentration of the semiconductor material in which the magnetic field sensor is formed and .delta.n is a variation in time of the charge-carrier concentration n.

Abstract: A device for measuring a weak magnetic field is disclosed. The device includes a substrate, a magnetic core having a high magnetic permeability and in the form of a surface film on a substrate, and at least two coils magnetically coupled to the magnetic core. A pulse generator is connected to one of the coils and is used to drive the magnetic core into intermittent saturation. The other coil is used to generate an output signal. The device can be used for measuring the weak magnetic fields associated with bank notes for identifying the values of the bank notes.

Abstract: An active current transformer has a primary conductor in which a current is to be measured and a secondary conductor in which a measuring current is generated in use. A feedback sensor provides an induced voltage and an amplifier receives a signal induced in the feedback sensor and generates the measuring current in the secondary conductor. The primary and secondary conductors are located in first and second magnetic circuits respectively, the first and second circuits having a common path over at least a part of their respective lengths. The feedback sensor is disposed on the common path of the first and second magnetic circuits so that, in use, the magnetic flux in the second path can be made substantially equal to that in the first path by operation of the amplifier in response to the voltage in the feedback sensor.

Abstract: The instant invention is a magnetic field sensor intermittently shielded by a controllable, saturable, magnetic shield. The magnetic shield is periodically driven into saturation by means of an excitation coil. The magnetic field to be measured is not disturbed by the shield during those time intervals when the shield is saturated. Intermittent sensing of the magnetic field to be measured, by the intermittently shielded magnetic field sensor, yields a magnetic field measurement unaffected by l/f noise and offset errors.

Abstract: An arrangement for converting a multiphase electric signal into a frequency is disclosed. Illustratively, the arrangement comprises an adder circuit for adding the individual phases comprising said multiphase signal. The arrangement also comprises one first polarity reversing switch for each phase in the multiphase signal. A voltage/current converter is connected downstream of the first polarity reversing switches. At least one second polarity reversing switch is connected downstream of the voltage/current converter. A control circuit generates a periodic switch-over signal for controlling the first and second polarity reversing switches. In addition, a constant current source is connected to an input of the second polarity reversing switch.

Abstract: An integrated circuit Hall element is disclosed. At least two current connection contacts and two sensor connection contacts are formed on the surface of the semiconductor body incorporating the Hall element. The active zone of the Hall element is located below the surface. A depletion region, depleted of mobile charge, is located between the surface and the active zone to provide isolation for the active zone, so that the Hall device output is linear and independent of changes in external temperature. A feedback circuit is provided to control the thickness of the depletion region.

Abstract: A recognition device for authenticating documents is disclosed. The recognition device comprises a reading head for optically scanning the documents. The reading head includes at least two modules of substantially identical construction, each of which is provided with a line of photosensors. The reading head also includes means for determining the spectral sensitivity of the modules. The recognition device also includes a conveying system for providing relative movement between the reading head and the documents being scanned. An evaluation means correlates signals provided by the photosensors with prestored values to control a sorter which sorts the documents based on their authenticity or falsehood.

Abstract: A circuit arrangement for summing power outputs is disclosed. The circuit arrangement is especially useful in connection with a multi-phase electricity meter. The arrangement includes a plurality of input circuits connected in sequence, each of which has a current-to-voltage converter and a multiplier connected to the current-to-voltage converter. A voltage-to-frequency converter is connected at the output of each multiplier. Starting, at least with the second input circuit in the sequence, an adder is connected to the voltage-to-frequency converter by means of two inputs of the adder. Two other inputs of the adder are connected to two outputs of the preceding input circuit in the sequence. Illustratively, two outputs of each adder form two outputs of the corresponding input circuit. A ternary encoder followed by a ternary decoder may be located between the outputs of one input circuit and the adder of the succeeding input circuit.

Abstract: The present invention is a method and apparatus for validating a valuable document such as a debit card. The valuable document includes a plurality of value markings arranged to form a code word. Illustratively, the value markings may be optical elements capable diffracting incident optical radiation. Alternatively, the value marking may be electrical elements such as safety fuses, diodes or transistors, the presence or absence of the electrical element representing a logic "1" or logic "0" respectively.In accordance with the present invention, the code word is first read to determine if it is valid. If the code word is valid, one or more value markings are erased, in each of plurality of erasing steps, until, illustratively after the final erasing step all of the value markings are erased. After each erasing step, the erased and remaining unerased validations markings form a new code word. If the sequence of new code words corresponds to a predetermined sequence of code words a signal is produced.

Abstract: A measuring transformer comprises a ferromagnetic core having a central branch. The central branch comprises at least one unit that is surrounded in part by an electrical conductor in the form of a U. Each unit of the central branch of the core has two outer air gaps and one or more central air gaps. Each outer air gap has length, that when measured in the longitudinal direction of the unit, is longer than the sum of the lengths of the one or more central air gaps. At least one magnetic sensor is contained in a central air gap of each unit and the central branch includes a total of at least two magnetic sensors. The measuring transformer is especially well suited for use in multifunction measuring instruments.

Abstract: A circuit arrangement for finding a sum of electrical power outputs for use in a multi-phase electricity meter is disclosed. The circuit arrangement comprises a plurality of multiplier circuits arranged in sequence. The sequence of multiplier circuits has two poles which form the output poles of the circuit arrangement. Each multiplier circuit comprises a Hall element, an amplifier, and a polarity reversing switch.